[PATCH AUTOSEL 5.10 24/51] spi: altera: fix return value for altera_spi_txrx()

[PATCH AUTOSEL 5.10 24/51] spi: altera: fix return value for altera_spi_txrx()

[Sasha Levin]

From: Xu Yilun <yilun.xu@intel.com>

[ Upstream commit ede090f5a438e97d0586f64067bbb956e30a2a31 ]

This patch fixes the return value for altera_spi_txrx. It should return
1 for interrupt transfer mode, and return 0 for polling transfer mode.

The altera_spi_txrx() implements the spi_controller.transfer_one
callback. According to the spi-summary.rst, the transfer_one should
return 0 when transfer is finished, return 1 when transfer is still in
progress.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1609219662-27057-2-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-altera.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index 809bfff3690ab..cbc4c28c1541c 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -189,24 +189,26 @@ static int altera_spi_txrx(struct spi_master *master,
 
 		/* send the first byte */
 		altera_spi_tx_word(hw);
-	} else {
-		while (hw->count < hw->len) {
-			altera_spi_tx_word(hw);
 
-			for (;;) {
-				altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
-				if (val & ALTERA_SPI_STATUS_RRDY_MSK)
-					break;
+		return 1;
+	}
+
+	while (hw->count < hw->len) {
+		altera_spi_tx_word(hw);
 
-				cpu_relax();
-			}
+		for (;;) {
+			altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+			if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+				break;
 
-			altera_spi_rx_word(hw);
+			cpu_relax();
 		}
-		spi_finalize_current_transfer(master);
+
+		altera_spi_rx_word(hw);
 	}
+	spi_finalize_current_transfer(master);
 
-	return t->len;
+	return 0;
 }
 
 static irqreturn_t altera_spi_irq(int irq, void *dev)
-- 
2.27.0

[PATCH AUTOSEL 5.10 29/51] spi: fix the divide by 0 error when calculating xfer waiting time

[Sasha Levin]

From: Xu Yilun <yilun.xu@intel.com>

[ Upstream commit 6170d077bf92c5b3dfbe1021688d3c0404f7c9e9 ]

The xfer waiting time is the result of xfer->len / xfer->speed_hz. This
patch makes the assumption of 100khz xfer speed if the xfer->speed_hz is
not assigned and stays 0. This avoids the divide by 0 issue and ensures
a reasonable tolerant waiting time.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1609723749-3557-1-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 2eaa7dbb70108..7694e1ae5b0b2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1100,6 +1100,7 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 {
 	struct spi_statistics *statm = &ctlr->statistics;
 	struct spi_statistics *stats = &msg->spi->statistics;
+	u32 speed_hz = xfer->speed_hz;
 	unsigned long long ms;
 
 	if (spi_controller_is_slave(ctlr)) {
@@ -1108,8 +1109,11 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
 			return -EINTR;
 		}
 	} else {
+		if (!speed_hz)
+			speed_hz = 100000;
+
 		ms = 8LL * 1000LL * xfer->len;
-		do_div(ms, xfer->speed_hz);
+		do_div(ms, speed_hz);
 		ms += ms + 200; /* some tolerance */
 
 		if (ms > UINT_MAX)
-- 
2.27.0